Means for determining the consistency of concrete mixtures



F 17, 1942- w. H. CLAGETT. JR ,273,750

- MEANS FOR DETERMINING THE CONSISTENCY OF CONCRETE MIXTURES Filed NOV. 9, 1938 2 Sheets-Sheet l INVENTOR.

j ,2 rag a 6272a Feb. 17, 1942. w. H. CLAGETT. JR 2,273,750

MEANS FOR DETERMINING THE CONSISTENCY OF CONCRETE MIXTURES Filed Nov. 9, 1938 2 Shets-Sheet 2 DRY Patented Feb. 17, 1942 UNIT-ED STATE S PATENT OFFICE S FOR DETERMINING THE CON SISTENCY OF CONCRETE MIXTURES William Horace Clagett, In, Mason City, Wash. Application November 9, 1938, Serial No. 239,712

7 Claims. (01. 265-11) with a concrete mixer in which the associated ingredients are manipulated or agitated in predetermined manner tending topile up the mix ture in one location when the water ratio is low, and with the mixture tending to level off as the water ratio increases. With such a concrete mixer, the pounds of force may be determined at one or more locations, and changes in this measured force may be taken as indicating a mixer shifts as the consistency, or workability I or fiowability, of the concrete is altered and influenced by variations in the water content in the ingredients or by changes in the mixing water, or through other variations of the factors afiecting consistency changes in the mix.

A further object is to provide means taking advantage of the fact that a batch of concrete.

when charged dry into a mechanical mixer assumes a certain definite slope with thematerial tending to pile up and establish a center of gravity, and as water is added or the workability or flowability of the concrete is increased this slope will flatten out to those vary and shift .the center of gravity in manner that can be predetermined and measured to indicate or show the consistency of the concrete mixture. V

Another object is to provide means by which the original character and the workability or consistency of the concrete mix can b determined and indicated and recorded, through the operation of the. concrete mixer, from the time the ingredients are placed in the mixer until the finished mass is discharged.

With the above and other objects and purposes in view, which will be apparent to those skilled in the art, or some of which are inherent inthe construction and use of the mechanism, my invention includes certain novel features of conparts, and certain novel steps and procedures,

relative change in the center of gravity'of the mix, due to the leveling off. Such force measurements, and changes therein, can and may be taken at various points or locations as reactions upon or from parts of the machine or apparatus or upon its foundation or supporting structure, and innumerable means for and methods of measuring the relative proportions of weight carried at various points to determine and measure the center of gravity of the mix may be resorted to, as conditions and particular installations may demand; the various applications and adaptations difiering perhaps primarily in the points or locations at which the forces are measured.

In the embodiment illustrated in Figs. 1 and 2, I have shown my invention in conjunction with a rotary concrete mixer of the tilting dumping type, as now quite commonly used in concrete construction and other'projects. The supporting structure I is mounted upon a foundation 2, or other suitable base structure, and a revoluble mixer cylinder 3 is carried for swinging or tilting movement on shafts or trunnions 4 mounted in suitable hearings on the supporting structure I. As such revoluble or rotatable and tiltable which will be hereinafter set forth in connection and part schematically shown, illustrating an embodiment of my invention.

Fig. 2 is an enlarged fragmentary sectional and diagrammatic view to better disclosed the indicating and recording means. 1

Fi 3 is a view similar to Figure 1 illustrating another embodiment. I

concrete mixing drums or cylinders 3 are of common and well known construction in this art, no attempt is here made to fully or particularly illustrate the constructional and mounting and operating features" thereof. Rotary concrete mixers are well known in the art, and in the present embodiment the showing is intended only to illustrate an adaptation and embodiment that may be an example of application to various types and constructions of concrete mixers operating and controlled in various manners.

With the present showing, a dumping and control cylinder 5 is employed to tilt the mixing In carrying out'my invention, embodiment is drum or cylinder 3 to either the position in which the ingredients of the batch are received and are mixed or to a position, as indicated by the dot and dash lines, in which the mixed concrete will be. discharged or-dumped through the open end 6. Obviously, various-hydraulic or pneumatic supply and controPmeans can beeniployed in connection with the drum tilting cylinder 5,\

,movement of the member 8.

or various mechanical and link and lever means may be suggested therefor, and as such mechanisms are now well known in this art no attempt is here made to show or describe or claim particular mixing apparatus or means.

A bearing member 1 is secured or anchored on the supporting structure I, or upon the base 2, or is otherwise secured to be substantially stationary, and a swingable member 8 is mounted for swinging movement on the bearing 1; as at 9, and has an offset swinging connection, as at III, with the dumping cylinder 5, this connection being ofi'set with respect to the line of thrust or force upon the dumping cylinder 5, so thatthe swinging member 8 is connected at the points 9 and I somewhat after the manner of a bell crank, with an extending pointer and indicating arm II rocked or oscillated as pulling or thrust force is exerted in a direction substantially coinciding with the axial line of cylinder 5. The pointer or indicating arm II may be arranged adjacent to a dial or indicator scale member I2, and thus as the force of thrust or pull is varied through variation in the disposition of the load in the mixing drum or cylinder 3, this pointer II will swing adjacent to the markings on the dial or indicator member I2 and will consequently indicate the change in the load and the shifting of the center of gravity of the mix.

The force or weight which the mixer structure may exert upon its foundation, and the thrust and pull upon the cylinder or linkage at must be compensated for and resisted, and this may be accomplished by anchoring a dash pot cylinder I3 in a relation to receive a piston I4 carried by a piston rod I5, which piston rod'is in turn pivotally connected at I6 with the swinging member 8. A coil spring H can be mounted in the dash pot to counteract or counterbalance the load force of the cylinder or drum 3 when swung to the mixing position, and the dash pot cylinder can be filled with oil or other suitable liquid or fluid to dampen and retard swinging I have shown a by-pass I8 establishing connection between the ends of the dash pot cylinder I3 with a valve I9 in this bypass and, obviously, various forms of spring or dash pot means can be employed to accomplish the desired purpose and end. To positively limit excessive upward swinging movement of the swinging member 8, an anchor bolt may be mounted or secured in the foundation or base structure 2 to extend upwardly through an opening 2I in the swinging end of the member 8, a safety stop 22 being provided at the upper end of this bolt or rod 20. It is perhaps preferable that the bolt or rod 20 be threaded for a suflicient length along its upper end to permit adjustment of the safety stop or nut 22.

Ordinarily, the mixing drum or cylinder 3 will be provided with mixer blades, as indicated at 23, and when the ingredients constituting the batch of concrete being mixed are placed in this mixing cylinder or drum, and the drum is rotated, two forces will be exerted upon the batch of material. The force of the mixer blades 23 tends to carry or move the concrete mixture'up and toward the rear of the drum or cylinder 3, due to its tilt when in the mixing position,-'so that the material is piled up or accumulated,

somewhat as'indicated by the line at 24; and, a

second force is also present tending toward a natural flow by gravity of the concrete material back down toward the front or mouth 6 of the mixing cylinder or drum 3. As the dry batch off due to the gravity flow as the batch becomes is mixed or agitated inthe cylinder or druni 3, v

the mechanical forces will tend to pile up the material substantially after the manner-as indicated by the line at 24; and, as the consistency becomes more uniform, due to an increase in uniformity of moisture distribution the batch being of more workable and flowable consistency will be influenced by gravity forces to level ofi to assume a surface contour somewhat after the manner indicated by the line at 25. As will be seen by reference to the drawing, this leveling of more uniform consistency and more workable will cause a considerably different distribution of the material within the mixing cylinder or drum 3, in consequence ofwhich the center of gravity of the batch will be correspondingly shifted. Thus, as water is added to the batch and is mixed in, the workability of the concrete is increased and the material flows so that the slope as the material is accumulated when more dry, flattens out, thus shifting the center of gravity from the dry position and permitting the operator to ascertain and determine the condition andwonsistency and workability or flowability of the particular batch at any and all times during the mixing operation. The spring I1 and the dash pot and associated parts I3 will assume the variations of load and will be responsive to shifting of the center of gravity so that the pointer portion I I of the swinging member 8 can be read against the dial or scale member I2 to give the operator an indication of the condition of the mixture. It will of course be understood that the cylinder or drum 3 can be tilted to discharge the mixture therefrom, and that the operation and indications will be accomplished with the cylinder or drum in the mixing position. When the mixer is up in the mixing position but empty, the spring II will be partly compressed due to the overbalancing weight of the structural parts. Then, With the addition of a charge of cement and aggregates into the. mixer, the spring is compressed to a point corresponding to the position of the center of gravity of the charge. The consistency as thus indicated by the pointer portion I I may vary due to variations in the mixture of the aggregate ingredients, and as the cylinder or drum 3 is rotated an accurate reading and determination of the mixture content or consistency can be taken. With the addition of (XII water, or other materials affecting the consistency or workability or flowability 'of the batch, the mass becomes more fluid, and from the approximate piled up relation as indicated at 24, the mass of the batch of material being mixed will flatten out, more after the manner indicated by the line 25, thus shifting the center of gravity of the mass and consequently changing the thrust and forces exerted through the dumping cylinder or linkage 5 upon the swinging member 8, and thereby altering the deflection of the spring and dash pot system a corresponding amount so that the pointer I I' indicates upon the dial or gauge scale portion a consistency measurement.

It may be necessary or desirable to employ a graphic or recording indicator, and the swinging member 8 adapts itself well to the use of various types of mechanical and electrical graphic and other recorder mechanisms. On the lever or swinging arm or member 8, away from the pivotal or swinging mounting thereof at 9, I connect the core 26 of a transmitting solenoid, and

at any suitable point I provide a recording mechanism including a recording solenoid core 21. Suitable circuit wires, generally indicated at 29, connect the transmitting solenoid coil 28 with the recording solenoid coil 29, and this wiring can be connected in any suitable circuit, as at 30, or to receive current from any other suitable source of supply! The is connected with a swinging arm 3|, the solenoid core being preferably counterbalanced by a weight 32 so that this swinging arm 3| will assume a central or normal position. A pen arm 33 extends from and is swingable by this swinging arm 3|, and this pen arm.33 works adjacent to and can be equipped to mark upon a recording sheet or tape 34 or upon any other suitabe sheet or disc or member. With this recording mechanism, movement of the swinging member or lever arm 8 will move the transmitting solenoid core 26 relative solenoid coil 29, and will thus impart corresponding movement to the recording solenoid core 21 within the recording solenoid coil 29. Consethe arm 3| will be swung and the pen quently, arm 32 will be proportionately moved so that as the sheet or tape 34 is moved a graphic record will be indicated and marked and kept thereon.

As graphic indicating and recording means are of many and various constructions and types, and are consequently well known in the art, no attempt is here made means or mechanism for moving the sheet or tape or record showing member 34, and I do not desire to specify any particular type or construction of recording means. I Obviously, employment of any such continuous or traveling graphic recording means will not only give an instant indication of the immediate operating condition, but by lining or otherwise marking the recording member 34 to indicate or denote time or intervals, a graphic record can be made and preserved to show the time of the day, the time or duration of operation of the machine for a particular mix or batch, and the consistency. throughout the entire time of operation, and any other'information or relative information or indication as may be desired.

In the embodiment disclosed in Fig. 3, the

- foundation or base structure 35 is shown as having openings therein to receive casings 36 and 31, which in the present instance are shown as dash pot casings or cylinders. The mixing drum or cylinder 38 is carried on a supporting structure 39, and as the center of gravity-of the load or batch within th e mixing cylinder or drum 38 varies, as between the relative positions generally indicated by the lines at 40 and 4|, force is exerted upon the supporting structure 39 tending to rock this structure.

Mounting bolts 42 and 43 are connected with the supporting structure 39 at spaced. apart points, and in positions to place pistons 44 and to the transmitting be connected to the arm recording solenoid core the transmitting solenoidcoil 53, and to infiuthe distribution of the load within the mixin cylinder or drum 38 and this swinging movement is in turn imparted to a pointer or indicating arm 50, which arm may work adjacent to a I dial orgauge 5|.

If desired, a transmitting solenoid core 52 can 50 to be moved within ence the recording solenoid core 54 movable in recording solenoid coil 55, which parts are embodied in a recording circuit 56. Graphic or other recording means, of any suitable and desired type, and in fact anysignal or indicating or recording means, can be actuated from the recording solenoid 54; and, where desired mechanical indicating or recording means can be connected to be agitated by movement of the indicator arm 50 or of the supporting member or structure 39. a

In the use of this embodiment, as the concrete batch becomes wet it flows toward the mouth to disclose any particular of the mixer drum or cylinder faster than the blades can take it up, until an equilibrium point is reached, perhaps somewhat corresponding to the line indicated at 4|. Simultaneously with this movement or shifting of the load and center of gravity of the batch, more weight is caused to be concentrated upon the forward-mountin bolt, or bolts, 42, accompanied by lessening of the weight carried by the rear supporting bolt or bolts 43. Thisaction somewhat compresses the bottom spring 46 and releases the bottom spring 41, thus causing tilting of the supporting member or structure 39 to correspondingly tilt or move the pointer arm up on the scale, thereby indicating the change in the consistency toward the we side.

45 thereon for reciprocatory movement in the cylinder-like casings 36 and 31. Springs are provided at 46 and 41 within the casings 36 and 31, below the pistons 44 and 45, so that the load of; the concrete mixer carried by the supporting In this embodiment, the supporting member or structure 39 constitutes a swinging part influ- Stabilizing springs 48 and '49 can be provided within .enced by changes in the center ofv gravity or Conversely, if the ingredients in the batch of concrete being mixed be dry, as for lack-of water, the blades will carry the material toward the rear of the mixer faster than it will flow by gravity toward the front, until the equilibrium point is reached somewhat corresponding to the line 40. At this point th center of gravity of the mass will be farther back in the mixer, thus putting greater weight on spring 41 and relieving or lessening the weight on spring 46. This shift will,cause the supporting structure or member 39 to be swung and will consequently shift the pointer down the scale or in the dry direction. As has been stated-springs 48 and 49 are provided to stabilize the mounting, and to still further stabilize, the casings or cylinders 36 and. 31 can be filled with oil or other suitable fluid or liquid. In some instances and adaptations the arrangement of the ,dash pots or casings 36 and 31 can be changed, as for example so that the load will be carried and shifts in the weight will be indicated, as the load accumulates at one side and recedes or levels off.

With this construction, the mounting and the operation are substantially the same as set forth, except for the fact that the changes in weight or center of gravity are measured from side to side, instead of from front to back. Such an arrangement will permit adaptation of my inventiton to and will allow applications thereof with a non-tilting type of drum mixer, and to other forms and mixers than the particular tilting type as here principally illustrated.

From the foregoing it will be seen that I have provided means for determining and measuring I and indicating and recording the consistency of.

a concrete mixture by determining the varying forces exerted due to piling up and leveling ofl or other shifts, of the batch of concrete being mixed, which changes or shifts will in effect indicate and be substantially influenced by variations in the center of gravity and in forces resultant therefrom.

While I have herein shown and described only certain specificembodiments and adaptations of my invention, and have set forth only certain steps and operations in carrying out the method, it will be appreciated that'many-changes and variations can be made in the form and construction and arrangement and mounting and associthe mixer under such shifting of material distribution, and indicator means connected with said mixer and actuated by such movement to indicate mixture consistency.

2. With a concrete mixer having a rotary drum and operating means therefor, baffle plates in said drum tending to pile up material being mixed at one end, said drum being mounted for yieldable movement under the force of the weight of the piled up material, and indicator means actuated by such yielding movement.

3. Means for determining the consistency of a concrete mixture during the mixing thereof comprising with a mixer in which material tends to pile up when lacking uniformity of consistency with leveling off as the mixture is of more uniform consistency, a yieldable mounting permitting movement of the mixer under such shifting of material distribution including a bell crank swinging member connected with the mixer, and

indicator means cooperable with said bell crank swinging member to indicate mixture consistency.

4. Means for determining the consistency of a concrete mixture for use with a mixing machine provided with a rotary drum having mixing blades therein tending to pile up the material at one end of the drum when lacking uniformity of consistency with leveling oif as the mixture is of more uniform consistency comprising a yieldable mounting permitting limited endwise tilting movement of said drum under such shifting material distribution, and indicator means connected with the mixer actuated by such yielding movement and having material consistency calibrations.

5. Means for determining the consistency of a concrete mixture during the mixing thereof for use with a mixing machine provided with a rotary drum having mixing blades therein tending to accumulate and pile up the material at one end when the material is lacking in uniformity of consistency with leveling off of the material occurring as the mixture is of more uniform consistency comprising, a mounting for said drum permitting axial swinging yielding in accordance with distribution of the material, means yieldably opposing such swinging movement, and indicating means actuated by axial swinging movement of said drum to indicate mixture consistency.

6. Means for determining the consistency of a concrete mixture comprising with an axially rotatable mixing drum having mixing blades tending to pile up material at one end of the mixing drum when lacking uniformity of consistency with leveling off as the mixture is of more uniform consistency, a yieldable mounting for said a concrete mixture during the mixing thereofcomprising a mixer of the type in which the center of gravity of the materials being mixed is shifted by changes in consistency during the mixing operation, having portions yieldable under the shifting of materials due to changes in consistency and including means responsive to yielding of said portions for indicating the consistency of the materials while the mixing operation is being performed.

WILLIAM HORACE CLAGETT, JR. 

